Airtel — not refunding my amount for unsuccessful recharge

I did a recharge of rs 399 on my airtel number from my airtel app on 17th of april but the recharge was unsuccessful, i did not receive the services but my account was debited with the amount. Since then i have contacted their customer care multiple times via phone and email but for no use. When you call them they tell you to call some other number or email and when you do that, they don't even reply. This has happened to me once before and i never got the refund for that too.